CNC impact load deflector sleeve and removable collar for cable and post protection

ABSTRACT

This patent application is submitted for a CNC/ILDS sleeve and RC removable collar designed to provide a means of protecting fence cables and posts. Without such protection a conventional rock fall protection fence frequently fails upon impact from large falling rocks spinning at a high angular velocity and with an immense momentum, as demonstrated in many rock fall-induced fence failures. CNC/ILDS sleeves embrace a cable or post to deflect falling rocks spinning at a high angular velocity and associated impact forces and, thereby, protect them by avoiding detrimental blows from the falling rocks. The RC (removable collar) is used when two different-size CNC/ILDS sleeves are used. This is to avoid a smaller sleeve from slipping into a larger one and to assure the protection that CNC/ILDS sleeve is designed for. Additionally, the RC collar also enhances the constructability and eases the maintenance of a rock fall mitigation fence system. In summary, the CNC/ILDS sleeve together with the RC removable collar embraces the fence cable and post, provides a means of their protection, and enhances the safety of traveling motorists.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention provides the protection for cables and posts (or columns) against the dynamic loads from rolling stones, vehicular impact, ice impact or other forms of transient loads. For instance, a rock fall mitigation fence (RFMF) is an ideal situation for the installation of CNC IMPACT LOAD DEFLECTOR SLEEVES (CNC/ILDS) and ROMOVABLE COLLAR (RC). The CNC/ILDS sleeves and RC collar can be installed on the cable holding the fence post, which, in turn, stretches rock fall drape net. The drape net, fence post, and cable constitute the rock fall mitigation fence system (RFMFS).

2. Description of Prior Art

A rock fall mitigation fence (RFMF) is frequently used to protect the traveling vehicles against potential hazards of falling rocks. The fence system is composed of the fence cable, fence posts, and rock fall drape net resting on the cable, which, in turn, is stretched and supported on the fence posts and cable anchors. The fence posts are embedded in rock and the cable is connected to the ground anchor embedded in rock. The RFMFS functions as a flexible fence system for retaining falling rocks by dissipating their dynamic energy during the back and forth swing upon rock impact. The mass of falling rocks varies a great deal. It can range from a few hundred pounds to many tons.

When falling from the hill/mountain top or slope, a falling rock gains momentum as it rolls down the slope. When it comes in contact with a RFMFS, the rock rotates at an extremely high angular velocity, can sever fence-supporting cables, and knocks out or severely bends fence posts, cuts anything it touches. The failure of the RFMFS allows the falling rocks to land on the highway or, in some cases, on top of a moving vehicle, as demonstrated in the rock fall in Georgetown, Colo. on Apr. 8, 2004.

To date the only mechanism for the failure prevention of the RFMFS is to use stronger nets, cables and posts. The literature search including the search on the US Patent and Trademark web site and the communication with fence installers did not reveal any other fence cable or post protection apparatuses as the CNC Impact Load Deflector Sleeve (CNC//ILDS) and Removable Collar (RC) submitted in this invention that deflect the moving rocks and impact force, and, thereby, reduce the chance of cable and post failures.

Accordingly there exists a need for a mechanism for deflecting falling rocks and impact force, reducing the chance of fence failure and enhancing the safety of the traveling public.

SUMMARY

The present invention, CNC IMPACT LOAD DEFLECTOR SLEEVE (CNC/ILDS), and Removable Collars (RC), reduces the impact load effect on both cables and fence posts by deflecting the falling rocks upon contact. FIGS. 1.a and b show the plan and side views of a CNC/ILDS and a RC. FIG. 2 shows a CNC/ILDS and a RC installed on a cable. The CNC/ILDS sleeve is a cylinder made of an appropriate material (usually steel) and has an appropriate diameter, length, and thickness for embracing a cable or post with a clearance for near frictionless rotation. The thickness and material type should be selected to provide sufficient strength to prevent the puncture by the rolling rocks. Upon contacting any high-speed rolling rock, the CNC/ILDS rotates nearly frictionless about the cable and, thereby, avoid cable cut. The sleeve and collar can be made of any materials deemed corrosion resistant, and sufficiently strong against the destructive force of rolling stones, wind, vehicular impact, or any other forms of impact force.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1.a and b show the plain and side views of a CNC/ILDS and a collar.

FIG. 2 CNC/ILDS sleeve and removable collars installed to protect the cable in an event of rolling stone impact.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1.a illustrates the plan and side views of a CNC/ILDS sleeve. It is a cylindrical tube of any appropriate material made to loosely embrace a cable or a post to allow its near frictionless rotation about the cable or post. This mechanism allows a CNC/ILDS sleeve to deflect a rolling rock upon contact and, thereby, reduce the failure potential of the fence cable. FIG. 1.b illustrates the RC collar that can be easily installed and removed from a cable for easy construction and repair. The collar is positioned between two different-size CNC/ILDS sleeves to prevent a smaller sleeve from slipping into a larger one. FIG. 2 shows a cable with CNC/ILDS sleeves and a RC collar between two sleeves.

Installation of CNC/ILDS

To mitigate the failure potential of a RFMFS, CNC/ILDS sleeves can be installed along the whole length of the cable and/or the post. The functionality of the CNC/ILDS is explained as follows:

-   -   A CNC/ILDS can rotate nearly freely around the cable and post         that they are protecting.     -   Upon contacting a sleeve, the impact force from a rolling rock         or any other impact sources, causes the sleeve to rotate.     -   The action of sleeve rotation deflects the impact force and         rock.     -   The deflection of the impact force reduces the damage potential         of the cable and post.

RC collars are installed between two CNC/ILDS sleeves at the lowest pint of the cable, a larger sleeve for protecting the connection just above the ground anchor and the smaller one for protecting the cable right above the cable connection the larger sleeve to prevent the smaller sleeve from slipping into the larger one. The fence system has to be structurally designed. Many instances of fence failures showed that the falling rocks severed the cables, and uprooted or severely bent the fence post. The failure of a RFMFS imposes a safety risk of traveling motorists from falling rocks as demonstrated in the recent rock fall event along Interstate Highway I70 near Georgetown, Colo. on Apr. 8, 2004. To reduce the risk of failure of a RFMFS, the fence cable needs to be protected from the cut by the large falling rock and the CNC/ILDS sleeve in this invention provides such protection. In an event of need for sleeve replacement, the RC collar enhances the constructability because it can be easily opened and removed, the large sleeve slips over the small sleeve and cable unbolted to allow sleeve removal and repair. 

1-5. (canceled)
 6. A guard device for protecting an object from damage by falling rocks or the like, the guard device comprising: at least one impact load deflector sleeve rotatably positionable about the object.
 7. The guard device of claim 6 and further comprising: a plurality of impact load deflector sleeves; and a removable collar positioned between each of the impact load deflector sleeves.
 8. The guard device of claim 6 wherein at least two of the impact load deflector sleeves have a different diameter.
 9. The guard device of claim 7 wherein the removable collar has a first collar portion and a second collar portion, the first collar portion being hingedly connected to the second collar portion.
 10. The guard device of claim 9 wherein each of the first collar portion and the second collar portion has a hinged side and an opening side, and further comprising: a locking mechanism for securing the opening side of the first collar portion to the opening side of the second collar portion.
 11. The guard device of claim 6 wherein each impact load deflector sleeve is substantially tubular having a diameter greater than the diameter of the object.
 12. The guard device of claim 6 wherein the object is selected from the group consisting of a cable and a post.
 13. A method for protecting an object from damage by failing rocks or the like, the method comprising: rotatably positioning at least one impact load deflector sleeve about the object; impacting the impact load deflector sleeve with a falling rock; and deflecting the falling rock by rotating the load deflector sleeve.
 14. The method of claim 13 and further comprising: providing a plurality of impact load deflector sleeves; and positioning a removable collar positioned each of the impact load deflector sleeves.
 15. The method of claim 14 wherein the removable collar has a first collar portion and a second collar portion, and further comprising: hingedly connecting the first collar portion to the second collar portion.
 16. The method of claim 15 wherein each of the first collar portion and the second collar portion has a hinged side and an opening side, and further comprising: securing the opening side of the first collar portion to the opening side of the second collar portion with a locking mechanism.
 17. The method of claim 13 wherein each impact load deflector sleeve is substantially tubular having a diameter greater than the diameter of the object.
 18. The method of claim 13 wherein the object is selected from the group consisting of a cable and a post. 